Diver access tube



July 23, 1968 B. GOEPFERT DIVER ACCESS TUBE Filed Aug. 10, 1966 FIG. 7

INVENTOR:

B. L. GOEPFERT HIS AGENT 3,393,525 7 Patented July 23, 1968 UnitedStates Pateflt'Office I ABSTRACT OF THE DISCLOSURE An apparatus forprotecting deep-sea divers whereby a tube having diver access openingsat each end is at-' tached to an offshore installation and provided witha diver-carrying elevator disposed within the tube and arranged foraxial movement.

This invention relates to deep-sea diving apparatus and moreparticularly to such apparatus associated with an offshore installationor platform for protecting a diver from water currents, ice floes, etc.,while descending to and ascending from an underwater location.

A need frequently arises in the operation of an offshore installation,like an oil or gas well production platform, to use a deep-sea diveroperating from the platform. Such divers may be required to makepipeline connections, perform operations On the platform, recover lostarticles, and the like. In tidal waters, where the ebb and flood tidesproduce relatively strong currents, a divers ability to ascend anddescend is greatly impaired and may even become hazardous due to thecurrents acting on the diver. For example, hazardous diving conditionsare experienced at the Cook Inlet in southern Alaska where tides rangingup to 30 feet are experienced. Such tides result in very rapid currentswhich dictate that the diver ascend and descend during slack tide; thatis, the transition period at high tide and low tide when currents are ata minimum. In addition, a diver is only capable of effectivelyperforming underwater functions during slack tide. Thus, a diverseffective work period is reduced if he has to also ascend and descendduring the slack tide period.

Therefore, it is apparent that if the diver-is permitted to remain onbottom for the full period of slack tide, his working time issignificantly increased. It is to this end that the present invention isdirected by providing a diving apparatus for protecting a diver fromwater" currents while descending and ascending. The invention alsoserves to protect a diver from ice fioes, debris and the like that maybepresent in the water.

In accordance with this invention, an offshore platform is provided witha vertical diver tube extending vertically from the platform down intothe water, and having access openings near the upper and lower ends. Theinterior of the tube is fitted with an elevator operated by a hoistlocated on the platform. In operation the diver enters the tube throughthe upper access opening and is lowered on the elevator. The diver thenremains in the tube until slack tide at which time he exits through thelower access opening and performs his work on the ocean floor. At theend of slack tide he again enters the tube and is brought to thesurface. The invention will now be described in greater detail withreference to the accompanying drawings in which:

FIGURE 1 is an elevation showing an offshore platform with a diver tubeattached;

FIGURE 2 is an isometric view in enlarged detail of the lower portion ofthe tube showing the access opening;

FIGURE 3 is a cross-sectional view of'the diver tube showing the diveraccess opening;

FIGURE 4 is a cutaway view of the tube showing the diver-carryingelevator;

FIGURE 5 is a cross-sectional view of the tube showing typical meansforattaching the tube to the platform;

FIGURE 6 is a detail elevation of the lower end'of the tube showing onemodification;

FIGURE 7 is a detail elevation of the lower end of the tube showinganother modification;

FIGURE 8 is a view taken in enlarged cross-section of one of the legs ofthe platform showing an alternative construction for the diver tube;and,

FIGURE 9 is a cross-section in elevation of one of the legs disclosingthe same alternative construction.

Referring now to FIGURE 1, an offshore installation to which the presentinvention is adapted is shown in the form of an offshore platform 10fixedly secured to an ocean floor 11 by means of legs 12. Secured to theplatform and extending to the ocean floor is a diver access tube 13. Thelower end of the tube, shown in detail in FIGURE 2, is formed with anaccess opening 14 large enough to permit a deep-sea diver and divingequipment to exit and enter the tube. The tube is preferably formed withhelical spoilers 31 about its exterior to minimize the eddy currenteffect caused by the water flowing past the tube although the use ofspoilers does not constitute a part of the present invention.

The tube may also be fitted with service conduits 34 running the lengthof the tube for supplying acetylene, air and the like from the platform10. The diver may make connection with the conduits by means of suitableconnectors 35 normally closed by check-valves.

FIGURE 3 shows a cross section of the tube taken through the accessopening. Although the diameter of the tube is not a significant part ofthe invention it will be observed that the diameter must be at leastlarge enough to permit a diver and diving equipment to ascend anddescend freely within the tube. Preferably, the tube is made somewhatlarger to permit a diver to carry tools, pipe, welding equipment and thelike to the ocean floor. The mouth of the opening 14 is preferablyfitted with a gasket 32 of rubber or other suitable material to protectthe divers suit and hoses. In addition, suitable hand rails 33 may 'beprovided adjacent the opening 14 to assist the diver in entering thetube 13.

A typical arrangement for fixedly securing the tube to the platform 10is shown by the cross section in FIGURE 5 which is taken through thetube where it joins the platform 10. Straps 15 surround the tube and aresecured to the platform 10 by suitable means such as welding. The tubeis preferably driven into the ocean floor 11 to anchor the lower end asshown in FIGURE 1, but the tube may also be terminated short of theocean floor as will be described later.

The diver tube is open at or near the upper end and carries an elevator16 attached to a hoisting cable 17 suspended from a crane 18. It will beapparent that manipulation of the crane hoist serves to lower and raisethe elevator within the diver access tube.

The elevator 16 may take any form suitable for carrying at least onediver. As shown, the elevator floor 19 is senii-circular in ordertopermit the diver to leave the elevator and pass by it within theconfines of the access tube. This elevator design is but a preferredform and others skilled in the art may utilize any particular elevatorshape without departing from the spirit of the invention. For example,the elevator may be constructed with two levels for carrying two diversdown the access tube at the same time.

The location of the tube on the offshore installation does not form apart of the invention, for it will be readily apparent that the tube maybe located anywhere on the installation so long as the upper end of thetube is accessible to a platform on the installation and the tubeextends substantially to the ocean floor. In addition, it may bedesirable to move the tube to different points on the installationsothat the diver exits nearer an intended work area; Also, a pluralityof tubes may be secured to the installation; for example, one at eachleg. Such an arrangement is particularly suitable for largeinstallations where the distance between legs may run several hundredfeet.

Although it is preferred that the diver access tub-e extend into theocean floor to secure the lower end as shown in FIGURE 1, the tube mayalso terminate short of the ocean floor as disclosed by the modificationshown in FIGURE 6. In this arrangement, the lower end of the tube may befixedly secured to the cross-bracing supporting the platform legs. Theaccess tube is open at the bottom to permit the diver to enter and exitdirectly through the end of the tube thereby obviating the need for anaccess opening door as shown in the preferred embodiment in FIGURES land 2. Since the end of the tube is not lodged in the ocean floor, thearrangement has the advantage that the tube may be more readilyrecovered to the surface.

A further modification is show in FIGURE 7 in which the diver accesstube is composed of two parts; a diver access tube 21 having a fiaredconnector end 22 and a tube extension 23 which is driven into the oceanfloor 11 and formed with an access opening 24. This modification permitsthe tube 21 and the extension 23 to be disconnected so that the accesstube 21 may be removed to the surface when the tube is not in use suchas, for example, during winter time when ice fioes may cause damage tothe diver tube. Also, when the tube is not in use it may be moved andemployed at another location. Since the extension 23 remains in theocean floor the diver tube may be readily reassembled by stabbing theaccess tube 21 onto the extension 23 from the surface. Although a flaredconnection 22 is shown, other connections may be utilized, for example abayonet type connector, without departing from the spirit of theinvention.

In still another form of the invention, the diver access tube may beincorporated in a leg 25 of a platform as shown in FIGURES 8 and 9.FIGURE 8 is a cross section of a platform leg 25 consisting of an outercylindrical member 26 and a spaced concentric inner member 27 Disposedwithin the space formed by the two members may be a plurality ofconduits 28 through which drilling operations may be performed orpilings driven to secure the platform leg. A diver access tube 29 ispositioned within the inner member 27 and extends the length of theplatform leg 25. Located near the lower end of the access tube is anaccess passage in the form of a conduit 30 passing through the inner andouter members 27 and 26 and communicating with the exterior of the legnear the ocean floor. The particular arrangement of the leg shown inFIGURES 8 and 9 is by way of example only and it will be apparent to oneskilled in the art that the tube may be adaptable to other platform legconstructions so long as there is an integral passage within the legextending substantially the length of the leg through which a diver maypass and an opening near the lower end of the leg forming a passage forthe diver to exit the leg and maneuver on the ocean floor.

4 In operation, a diver enters the tube near the upper end and stepsontothe elevator 16 or if desired the diver may first step onto theelevator which may then be subsequently placed in the open upper end ofthe tube. After the diver is positioned on the elevator in the tube thecrane 18 and its hoist (not shown) lowers the elevator until theelevator is positioned near the access door or opening 14. This entireoperation may be performed during ebb or flood tides since the diverwill be protected by the access tube. At slack tide When currents are ata minimum the diver may exit from the tube through opening 14 to carryout his work function on the floor of the ocean. At the end of slacktide the diver re-enters the tube where he is brought to the surface bythe elevator 16. It will be observed that sea water is in opencommunication with the tube through the opening 14 and thus assumes thesame level in the tube as the ocean itself.

In the event that it is not desirable to lower the diver the entiredistance on the elevator 16, the elevator may be lowered to some pointbelow the water surface after which the diver may leave the elevator anddescend through the water in a conventional manner. The semi-circularelevator floor 19 shown in FIGURE 4, provides sufficient space betweenthe elevator floor 19 and the interior of the tube to permit the diverto pass by the elevator for descending in a conventional manner.

The mode of operation for the modification shown in FIGURE 7 and alsofor the modification shown in FIG- URES 8 and 9 is the same as describedabove. In the modification shown in FIGURE 6 the diver merely exitsthrough the open bottom of the access tube since the tube terminatesshort of the ocean floor.

Having thus described my invention, what I claim is: 1. An apparatus forprotecting a deep-sea diver from water turbulence, ice floes, etc.,while diving from an offshore installation comprising in combination:

an offshore installation having a plurality of substan tially verticalunderwater structural members positioned on the floor of a body of waterand a platform portion positioned on said members above the surface ofsaid water; a diver tube extending down into said water and having theupper end terminating near said platform;

said tube being formed with a diver access opening in the upper end inopen communication with the atmosphere and a diver access opening nearthe lower end in open communication with said body of water wherebywater is maintained in said tube at a level substantially equal to thesurface of said body of water;

means for securing said tube to said offshore installation; adiver-carrying elevator disposed within said tube and arranged for axialmovement therein; and,

hoist means located on said platform and connected to said elevator toat least raise said elevator within said tube.

2. The apparatus as defined in claim 1 wherein said elevator is spacedfrom one side of said tube a distance sufiicient to permit a diver anddiving equipment to pass by said elevator.

3. The apparatus as defined in claim 1 further including at least oneservice line attached to said platform in communication with a fluidsource on said platform and terminating near the bottom of said tube.

4. The apparatus as defined in claim 1 wherein said diver tube and saidunderwater structural members extend into the floor of said body ofwater.

5. The apparatus as defined in claim 1 wherein said diver tubeterminates short of the floor of said body of water.

6. The apparatus as defined in claim 5 further including a tubeextension connectable to the lower end of said diver tube and extendinginto the floor of said body of water, said extension having a diveraccess opening 5 6 near the floor of said body of Water, and said divertube References Cited being connectable to said extension bymanipulation of UNITED STATES PATENTS said diver tube from saidinstallation.

7. The apparatus as defined in claim 1 wherein said 597,597 1/1898 Webb6182 underwater structural members comprise legs rigidly 5 819,317 5/1906 ShTeWSbllfY mounted on the floor of said body of water. 1,029,7696/ 1912 Smith 182-48 8. The apparatus as defined in claim 7 wherein said1,048,194 12/1912 Mitchell 61-82 tube is formed integrally Within a legof said platform 2,587,835 5/1952 Goodman 61-82 and said leg includesdiver access openings near the upper and lower ends thereof. 10 REINALDOP. MACHADO, Primary Examiner.

